[P-hack]

Hi EM!

I recently picked up a 2004 prius, interesting car, I am used to small stick shift cars (and P&G and etc).

I was trying to get my head around it and reading all the online opinions, including varying opinions about driveline efficiency.

referring to:
eahart.com/prius/psd/

It seems apparent that it is basically a series hybrid at 0mph, and that even at higher speeds it relies on generator torque to drive the wheels directly and thus is a balance of series/parallel.

So, the question is, can hiway efficiency be improved by not relying on the electrical transmission of torque? I.e. add a brake band to MG1?

Example:
Lets say ICE bsfc peak is at 3000 rpm
MG1 is braked at 0 rpm
MG2 is at 73mph/4300rpm

I am not sure how many hp you need at 73 mph, 35? maybe the engine would be 50% loaded? so you go from 230g/kwh to 265? (%15 difference), so maybe go a little faster?

But the idea is that with mg1 physically locked, it becomes essentially direct drive (with mg2 "freewheeling") and no xfer of power.


And on the other end, if you could put a brake band on the ICE, would it reduce the electrical demands when trying to drive 41mph on electrical only.


Note, I am not familiar with all the software/control nuances, so this is just a high level question about the drivetrain hardware (before I contemplate hacking the crap out of my prius) Perhaps there are already brakes in place, or the holding/opposing torque current demands are not large.

Thanks.